Performance-aware logic operations for generating masks

Abstract

Stress engineering for PMOS and NMOS devices is obtained with a compressive stressor layer over the PMOS device, wherein the compressive stressor layer has the shape of a polygon when viewed from a top down perspective, and wherein the polygon includes a recess defined in its periphery. The NMOS device has a tensile stress layer wherein the tensile stressor layer has the shape of a polygon when viewed from the top down perspective, wherein the polygon includes a protrusion in its periphery, the protrusion extending into the recess of the first stressor layer. Thus, stress performance for both devices can be improved without violating design rules.

1. A semiconductor device comprising:
 a substrate; 
 a PMOS transistor comprising:
 a first gate over the substrate; 
 a first source region adjacent to the first gate; 
 a first drain region adjacent to, and on an opposite side of the first gate than, the first source region; and 
 a first stressor layer over the first gate, the first source region, and the first drain region, wherein the first stressor layer has a compressive stress, and wherein the first stressor layer has the shape of a polygon when viewed from a top down perspective, the top down perspective being defined as from a perspective orthogonal to a major surface of the substrate, and wherein the polygon includes a recess defined in its periphery, and 
 
 an NMOS transistor adjacent the PMOS transistor, the NMOS transistor comprising:
 a second gate over the substrate; 
 a second source region adjacent to the second gate; 
 a second drain region adjacent to, and on an opposite side of the second gate than, the second source region; and 
 a second stressor layer over the second gate, the second source region, and the second drain region, wherein the second stressor layer has a tensile stress, and wherein the second stressor layer has the shape of a polygon when viewed from the top down perspective, and wherein the polygon includes a protrusion in its periphery, the protrusion extending into the recess of the first stressor layer. 
 
 
     
     
       2. The semiconductor device of  claim 1 , wherein the first stressor layer and the second stressor layer are contact etch stop layers. 
     
     
       3. The semiconductor device of  claim 1 , wherein the first stressor layer and the second stressor layer have a first dimension and a second dimension in a direction parallel to longitudinal directions of the first gate and the second gate, respectively, and wherein the first dimension is greater than the second dimension. 
     
     
       4. The semiconductor device of  claim 1 , further comprising an isolation region interjacent the PMOS transistor and the NMOS transistor and wherein the recess in the first stressor layer and the protrusion in the second stressor layer are formed over the isolation region. 
     
     
       5. The semiconductor device of  claim 4 , wherein the isolation region comprises a shallow trench isolation. 
     
     
       6. The semiconductor device of  claim 1 , wherein the second stressor layer at least partially overlaps the first stressor layer. 
     
     
       7. The semiconductor device of  claim 1  further comprising a contact contacting the first gate and passing through the first stressor layer. 
     
     
       8. A semiconductor device comprising:
 a first transistor formed in a substrate; 
 an isolation region adjacent the first transistor; 
 a second transistor formed in the substrate adjacent the isolation region and on an opposite of the isolation region relative the first transistor; 
 a first stressor layer overlying the first transistor, the first stressor layer imposing a compressive stress to a channel region of the first transistor, the first stressor layer occupying a first defined region of the substrate, the first defined region extending in a first direction and a second direction orthogonal to the first direction; 
 a second stressor layer overlying the second transistor, the second stress layer imposing a tensile stress to a channel region of the second transistor, the second stress layer occupying a second defined region of the substrate; and 
 an overlap region wherein the second defined region protrudes into the periphery of the first defined region, and wherein the overlap region extends in the first direction and the second direction, but does not extend to the full extent of the first defined region in either the first or the second direction. 
 
     
     
       9. The semiconductor device of  claim 8  wherein the first transistor is a PMOS transistor and the second transistor is an NMOS transistor. 
     
     
       10. The semiconductor device of  claim 8  wherein the overlap region overlies the isolation region. 
     
     
       11. The semiconductor device of  claim 8  wherein a portion of the second stressor layer overlaps a portion of the first stressor layer. 
     
     
       12. The semiconductor device of  claim 8  wherein a portion of the first stressor layer and a portion of the second stressor layer merge. 
     
     
       13. The semiconductor device of  claim 8  wherein the overlap region has a shape of a polygon when view from a top down perspective, the top down perspective being defined as from a perspective orthogonal to a major surface of the first stressor layer. 
     
     
       14. The semiconductor device of  claim 13  wherein the polygon has a shape of a rectangle. 
     
     
       15. The semiconductor device of  claim 8  wherein the first direction is parallel to a channel width of the first transistor and the second direction is parallel to a channel length of the first transistor. 
     
     
       16. The semiconductor device of  claim 15  wherein the overlap region extends the full length of the second defined region in the first direction. 
     
     
       17. The semiconductor device of  claim 8  wherein the first stressor layer is a first etch stop layer and second stressor layer is a second etch stop layer. 
     
     
       18. A semiconductor device comprising:
 a first transistor formed in a substrate and having:
 a first gate having a major longitudinal axis extending in a first direction parallel to a plane of a major surface of the substrate; 
 a first diffusion region having a major longitudinal axis extending in a second direction in the plane, orthogonal to the first direction; and 
 a first stressor layer axis extending in the first direction and the second direction, the first stressor layer having a shape of a polygon in the plane parallel, the polygon having recess portion therein; and 
 
 a second transistor formed in a substrate and having:
 a second gate having a major longitudinal axis extending in the first direction; 
 a second diffusion region having a major longitudinal axis extending in the second direction; and 
 a second stressor layer extending in the first direction and the second direction, the first stressor layer having a shape of a polygon in the plane, the polygon having protrusion portion extending into the recess portion of the first stressor layer. 
 
 
     
     
       19. The semiconductor device of  claim 18  wherein the recess portion and the protrusion portion overly an isolation region interjacent the first and second transistors. 
     
     
       20. The semiconductor device of  claim 18  wherein the first stressor layer is a first etch stop layer that imposes a compressive strain on a first channel region of the first transistor and the second stressor layer is a second etch stop layer that imposes a tensile stress on a second channel region of the second transistor.